There are many aspects to providing stage lighting. These include spotlights, flood lights, colors and moving lights. A significant aspect of such stage lighting is the projection of images, in the form of a silhouette, onto the stage to a backdrop, a screen or the performers themselves. The conventional light pattern generator for projecting such a silhouette image is termed a "gobo". The typical gobo is made of a sheet of metal which has the desired image cut in the sheet as an opening for shaping a light beam. The metal sheet, with the cut-out image, is placed in the beam from a spotlight so that the portion of the beam that passes through the sheet is shaped to correspond to the image cut in the gobo. The image is typically passed through a lens so that the image can be focused on a desired portion of the stage.
The gobo is mounted directly in the beam of light. Since stage lighting uses intense light beams, the gobo can become very hot. In fact, it is not unusual for a gobo to become so hot that it begins to glow with a cherry red color. To combat the extremely high heat, gobos have been fabricated of heat resistant metals, such as stainless steel. However, even gobos made of this material have a relative short lifetime and require frequent replacement.
The conventional gobo is also limited as to the configurations that can be produced. Since all of the metal elements of a gobo must be supported, there must often be unwanted support members included in the design. As an example, it is impossible to produce a complete ring design because support members must extend from the exterior to support the interior metal.
Therefore, in view of the need for the projection of images as a part of stage lighting and the short lifetime of conventional gobo image producers, as well as the limitations on designs, there exists a need for an improved light pattern generator which can project a desired image, while at the same time withstanding the high temperatures present within a light fixture.